[JURIST] Michigan, joined by 19 other states, filed an application [text, PDF] in the US Supreme Court [official website] this week to enjoin the Mercury and Air Toxics Standards (MATS) [materials, PDF] pending a petition for certiorari. MATS, which requires installation of technology in electricity-generating power plants focused upon curbing air pollution caused by mercury and other harmful materials, was enacted pursuant to the Environmental Protection Agency (EPA) [official website] interpretation of a portion of the Clean Air Act (CAA) [materials, PDF]. The states contend that the EPA went beyond “the bounds of reasonable [statutory] interpretation” in reading the CAA to allow the agency to “ignore cost when deciding to regulate power plants.” In particular, the application states that while the CAA grants the EPA the ability to make rules and regulations which are “appropriate and necessary,” the EPA “must consider cost—including, most importantly, cost of compliance.” The states claim that the EPA has not conducted a proper cost-benefit analysis of MATS and that the regulations are already imposing irreparable economic and procedural costs upon power plants. The EPA has stated that it will have enough evidence to issue a final finding on the matter in the near future, ultimately granting it authority under the CAA to support its rule.

In December the US Court of Appeals for the District of Columbia Circuit [official website] ruled that the EPA could continue enforcing the rule while it conducts the cost-benefit analysis. The decision came after the Supreme Court ruled [JURIST report] last June that the EPA could not make regulations regarding the toxic emissions of power plants without considering costs. The Supreme Court sent the EPA cases back to the appellate level to run the cost-benefit analysis to determine the validity of the regulations on power plants. The EPA anticipates completing its study by mid-April.